Detachable manhole-step.



. PITTS.

DETAGHABLE MANHOLE STEP.

APPLICATION FILED JUNE 11, 1912.

Patented Apr. 14, 1914.

9M WM TTNTTED %TATE@ PATENT @FT TQE.

ALFRED M. PITTS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO WALTER F. PITTS, OF

, BOSTON, MASSACHUSETTS.

DETACHABLE MANHOLE-STEP.

1&93204.

Specification of Letters Patent.

Patented Apr. 1d, 1914.

Application filed June 11, 1912. Serial No. 703,041.

To all whom it may concern Be it known that I, ALFRED M. Prrrs, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented new and useful Improvements in Detachable ll Tanhole-Steps, of which the following is a specification. 7

My invention relates to detachable man hole steps, and its objects are to render the interior of man holes more accessible, to provide a ready means for firmly attaching and easily detaching. man hole steps, and to simplify and render more efiective the construction of the several parts.

My invention primarily consists in constructing a casting designed to be inserted within and to form part of the wall of the man hole itself, and having therein recesses which engage with arms or lugs upon the manhole step and detachably secure the same against movement in any direction.

My invention further consists in various improvements and novel arrangements of parts more particularly hereinafter described and claimed.

Attention is directed to the drawing in which similar letters of designation refer to similar parts throughout the several views.

Figure 1 is a section of a concrete man hole, showing several of my improved steps duly installed; Fig. 2 is a plan view of my invention showing, the insert partly in section and the adjacent concrete wall Fig. 3 is a vertical section on line 33 of Fig. 2 looking in the direction of the arrows.

Referring to the drawing, the step 1 is constructed preferably of metal and is formed with the tread 5 and the arm 6. Preferably I construct the tread 5 in the form of a loop, but any convenient well known form of tread may be used which is suitable for the purpose. The arm 6 I prefer to make cylindrical in form and integral with the tread 5, and bears thereon the key 7 To secure the step 4 to the concrete wall 17, I employ the metallic insert 8, which may be forged or cast, and is embedded in the wall 17 at the time the same is constructand 16 are left accessible.

ed. As will be seen in Fig. 2, one side of the tread 5 abuts against the face of the in.- sert and wall adjacent thereto, which is an important feature since it assists in giving steadiness and rigidity to the step 4:. The insert 8 preferably bears upon the rear portion thereof the metallic bar 13, which affords a firm anchorage in the concrete. The

main portion 10 of the insert is provided with the cylindrical recess 9 which is shaped to engage with the arm 6. The recess 9 has a longitudinal groove or key-way 11, terminating in' a transverse segmental recess 12 and the key 7 on the arm 6 may be slid along said groove and turned into the segmental recess to lock the arm 6 into the insert.

To look the step 4: securely in position, I prefer to use, in addition to the key 7 and ways above described the pin 15, which as shown in Fig. 2 passes through an opening in the portion of the tread adjacent to the wall and engages with the opening 16 of the insert.

My invention when used as a means for gaining access to manholes is preferably installed as follows: Within the form or mold of the cars 18 integral therewith which are nailed or screwed to the wood of the form.

This arrangement brings the face of the insert flush with the face of the wall of the manhole, so that when the concrete is poured into the mold and hardens, the openings 9 After the inserts 8 have been duly installed, the attachment of the steps is a simple matter. Each step is held in a vertical position and the end of the arm inserted into the recess, the key 7 engaging with the keyway 11. The step is then pressed home, and upon the key registering with the segmental recess 12, is turned into a horizontal position and locked therein by means of the pin 15. To detach the step the above operations are reversed.

In man holes as ordinarily constructed, it is the custom either to employ ladders to gain access to the same, or after the man hole is built, to provide steps by boring holes within the wall thereof and permanently affixing in said holes the ends of metallic loops or rungs which placed one over the other serve as a ladder. WVhere the walls of the man hole are of iron, steel, or other metal, this method of securing steps has been found feasible, though subject to the objections of being a somewhat expensive operation, and of providing an obstruction which itis impossible to remove and replace when desired. hen, however, concrete is used for man holes after the same have been built, this method of attaching steps is found to be inoperative for the reason that concrete of itself is not sufliciently hard or tough for holes in the same to secure a nut or the head of a bolt without reinforcement of some kind. WVhile building the manholes of concrete, steps might, it is true, be embedded therein and if properly reinforced serve the purpose of obtaining access to the interior of the hole; but such installation would be permanent and would not admit of removing and replacing the step when desired.

I have found that the present method of permanently installing steps is defective for two reasons :first, because when the step breaks down or rusts out it is difficult in the case of an iron man hole to remove and replace the same except at great expense and is impossible to install in the case of a cement man hole without practically reconstructing the same, and, second, because where steps are immovably secured to the wall they afford obstructions to matter which is hoisted in and out by a derrick, steam hoist or other means. There is, therefore, a present demand for a step for man holes which can be easily affixed and re moved, whether the man hole be of metallic or concrete construction. In the case of my invention, the insert is the only permanent feature and in itself affords no obstruction. lVith concrete construction, such insertmay be readily and cheaply installed, and with metallic constructions the insert may be cast integral with some section of the pipe.

In view of the increasing use of concrete for man holes, my invention will be found of great utility, being especially adapted for use in man holes of such material, although not limited in its usefulness to this material alone.

Where my invention is used, the steps 'may either be installed for a short time while they are being actually used, or they may be left in place until such time as their removal may be necessitated by reason of wear and tear or any other reason.

The steps being interchangeable may be used again and again in different man holes where their use may be required, one set of steps thus serving in place of many sets installed for long periods if desired.

While I' have described my invention with particular reference to man holes, I by no means desire to be understood as limiting the scope of my invention solely to such use, since, as is obvious, my improved. step and insert could be used to advantage in many other connections.

What I claim and desire to secure by Letters Patent is,

1. A detachable man-hole step comprising an insert member provided with an elongated socket member having a longitudinal groove terminating in a segmental recess, a tread member having a shank adapted to fit snugly in said socket, a projection on said shank to enter said groove and be retained in said recess when said tread is turned in supporting position, and means for positively preventing said tread'from rotation.

2. A detachable man-hole step provided with an insert member provided with an elongated socket having a longitudinal groove terminating in a segmental recess, a tread member frictiona-lly engaging the face of said insert and provided with a shank fitting within said socket, said shank having a project-ion to enter. said groove and be retained in said recess when said tread is turned in supporting position, and a pin passing through said tread and entering a portion of said insert for positively retaining said tread against rotation.

3. A detachable man-hole step provided with an insert member provided with an elongated socket having a longitudinal groove terminating in a segmental recess, a tread member frictionally engaging the face of sald insert and provided with a shank fitting within said socket, said shank having a projection to enter said groove and be retained in said recess when said tread is turned in supporting posit-ion, and a pin for positively locking said tread against rotation.

4. A'detachable man-hole step comprising an insert member provided with an elongated socket having a longitudinal groove terminating in a segmental recess, a tread member frictionally engaging the face of said insert and provided with a shank fitting within said socket, said shank having a projection to enter said groove and be retained in said recess when said tread is turned in supporting position, a shoulder on said socket member, and a pin passing through said tread and engaging said shoulder for positively locking said tread against rotation. j

5. A detachable man-hole step comprising an insert having an elongated socket pro .vided with a longitudinal'groove terminati ing in a segmental slot, a shoulder formed on the end of said socket member, a tread member frictionally engaging said socket member, an provided with a shank closely fitting Within said socket a projection on In testimony whereof I have herennto set said shank adapted to enter said groove and my hand in presence of two subscribing witbe retained within said recess when said nesses, this 10th day of June 1912.

tread is turned into supporting position,- ALFRED M. PITTS. 5 and means connecting said tread and shoul- Htnesses:

der to positively lock said tread against ro- HUBERT M. CHASE,

tation. JOSEPH L. TI-IACHER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

